The following abbreviations that appear in the ensuing disclosure are defined as follows:    3GPP Third Generation Partnership Project    3.9G Long Term Evolution UTRAN    BS base station (referred to as Node B in some systems)    DL down link    DRX discontinuous reception    DSP digital signal processors    FDM frequency division multiplexed    HW hardware    FFT fast fourier transform    LTE Long Term Evolution    OFDM orthogonal frequency division multiplexing    PSCH primary synchronization channel    RAN radio access network    RNC radio network controller    SSCH secondary synchronization channel    SW software    UE user equipment    UTRAN Universal Terrestrial Radio Access Network
Orthogonal Frequency Division Multiplexing has been proposed in 3GPP for DL LTE UTRAN. Reference in this regard may be had to “Principles for the Evolved UTRA radio access concept”, Alcatel, Ericsson, Fujitsu, LGE, Motorola, NEC, Nokia, DoCoMo, Panasonic, RITT, Samsung, Siemens, WG1 Ad Hoc on LTE UTRA, R1-050622, Sophia Antipolis, France, 20-21 Jun. 2005. A frame containing a preamble was outlined in 3GPP (see “Physical Channels and Multiplexing in Evolved UTRA DL”, NTT DoCoMo, WG1 Ad Hoc on LTE UTRA, R1-050590, Sophia Antipolis, France, 20-21 Jun. 2005).
Initial cell acquisition requires time and frequency synchronization at user equipment prior to computation of receiver algorithms. A cell/sector specific pilot sequence needs to be identified to allow channel estimation and channel equalization. Furthermore, practical algorithms (at least in terms of processing complexity) to estimate and correct timing and carrier offset for cell acquisition are required before receiver algorithms can be processed. However, the cell-specific pilot sequence is unknown during the initial cell acquisition stage. A robust mechanism is needed to detect the pilot sequence for channel estimation.